Which position should be selected for the results assessment? Although the irradiation levels are slightly lower on both sides, our recommendation is that all samples can be used for the results evaluation, but it is recommended that the sample position is changed during the test. If the customer does not wish to reposition the sample or requires irradiance uniformity of >90% at all positions, then they may choose to leave the end clips blank. https://www.qinsun-lab.com/aging-tester/index.html